San Diego County, San Diego Rat Control Situation:
Hi David, Is a UV blacklight still useful, exterior-wise, if it rains after the rodents leave their urine stains? I am in the process of performing exterior maintenance to better exclude my roof rats. 1) I have a 25 year old cedar shake roof in San Diego California with openings under each shake along the rake edge of the roof at the gable ends of my house. There's no drip edge, i.e. under the shakes I have roofing paper (now somewhat curled) that runs more or less up to and rests right atop the fascia board. Because I have skip sheathing, and since the cross section of a shake is a wedge that is up to one inch at the upper, thick end, this appears to create many huge entry points along the rake edges even though the sheathing is rabbeted into the fascia board. As a result, I'm thinking of getting a UV blacklight to use outside the house to sleuth for urine stains along the upper edge of the gable end shakes and fascia boards. My question is, how easily does the winter rain wash away the urine, rendering this a pointless exercise? 2) I noticed a new product called "rat-out gel" and was thinking of applying it along the rake edges mentioned above. Or, maybe I should just buy many rolls of X-Clude and use that instead. Or maybe both. Any comment? Thanks very much for your website, Doug
My response: First off, I do not have experience using UV lights to detect rat urine. But I do suspect that rain will severely limit the effectiveness of this approach. I have never heard of Rat-Out Gel or XClude, but I typically stick to physical barriers rather than repellent type devices. If your roof makes this impossible, you might have a tough time keeping the rats out.
San Diego Rat Control Tip of The Week
What Are The Mating Habits Of The Black Rat And Norway Rat?
Black Rat
The ship rats have a polygamous mating framework, where a single male mates with various females. As a rule, the prevailing male is a successful breeder. These rats mate from March to November. The development or conception period goes on for 21 - 29 days, yielding 3 - 5 litters of 1 - 16 young (with a normal or average of 7) every year. Children of this species are brought into the world altricial. Their eyes open just at 15 days old, while hairs show up before the end of the nursing period. The young ones are weaned, and become independent at 3 - 4 months of age.
Norway Rat
Norway rats generally build homes in below-ground burrows or at ground level. Homes might be fixed with shredded paper, fabric, or different stringy materials. Litters of 6 to 12 young ones are brought into the world 21 to 23 days after conception. Baby rats are stripped, and their eyes are shut; however, they develop quickly. They can eat solid food at 2 1/2 to 3 weeks. They become independent at around 3 weeks to about a month and arrive at reproductive maturity at 3 months old, sometimes as early as 8 weeks. Female Norway Rats may come into heat every 4 or 5 days, and they may even mate a day after a litter is conceived. The average female rat has 4 to 6 litters per year and may effectively wean at least 20 offspring every year.
